JP5376914B2 - Radiation transmission test apparatus and test method for plant equipment - Google Patents

Description

  The present invention relates to an apparatus for performing a radiation transmission test when repairing plant equipment and a test method using the same, and more particularly, to radiation transmission of a new circumferential weld line of a tubular member such as a nozzle or an elbow of a steam generator. The present invention relates to a technique for improving a test so that it can be performed efficiently.

  An outline of the primary cooling equipment system of the pressurized water reactor is shown in FIG. 10, an outline of the lower part of the steam generator is shown in FIG. 11, and an outline of the reactor vessel 2 is shown in FIG. The reactor vessel 2 provided inside the reactor containment vessel 1 has a loop composed of a steam generator 3, a primary coolant pump 4 and a pressurizer 5 depending on the output of the reactor. Is provided. Then, the primary coolant heated in the reactor vessel 2 is sent out from the outlet nozzle 6 of the reactor vessel 2, and is sent from the inlet nozzle 7 of the steam generator 3 into the water chamber of the steam generator 3.

  The water chamber of the steam generator 3 is partitioned into an inlet side 8 and an outlet side 9, and the primary cooling water sent to the inlet side 8 is sent to a number of heat transfer pipes 10 to receive secondary cooling water and heat. After exchanging, it reaches the outlet side 9, returns from the outlet nozzle 11 of the steam generator 3 through the primary cooling pump 4, and returns from the inlet nozzle 12 of the reactor vessel 2 to the inside of the reactor vessel 2.

  By the way, in the pressurized water reactor, there are welded parts using 600-series inconel-based alloy at the outlet nozzle nozzle base of the reactor vessel 2 and the inlet nozzle nozzle base part of the steam generator 3, and when the inspection is performed Cracks may be found. The repair work performed in this case includes a method of removing the crack and performing overlay welding, and a method of cutting the weld and replacing it with a new pipe.

  An example of repair work by replacement is shown in FIGS. In the repair work by this replacement, as shown in FIG. 13, the elbow 13 is removed by cutting a part 7 a of the inlet nozzle 7 including the crack detection site. In addition, the cutting position of FIG. 13 shows an example, and this invention is not limited to the cutting position of illustration.

  Next, groove processing of the inlet nozzle 7, the new elbow 14, and the new nozzle 15 is performed. And as shown in FIG. 14, the new elbow 14 and the new nozzle 15 are attached, welding is performed, and a final finish is performed.

  A radiographic test is required for the new circumferential weld lines 16, 17, and 18 that have completed the final finish. At this time, since these peripheral weld lines 16, 17, and 18 are thick, it is desirable to place a radiation source inside and paste a film on the outer peripheral portion to perform a radiation transmission test. However, since the radiation dose is high in the portion and the inside of the water chamber of the steam generator 3 is a poor workability, the exposure dose is large, and the new circumferential weld line 18 is particularly difficult.

  Accordingly, an object of the present invention is to provide a radiation transmission test apparatus and a test method capable of improving workability while reducing the exposure dose of an operator when performing a radiation transmission test in a pressurized water reactor in which repair work has been performed. Is to provide.

The radiation transmission test apparatus according to claim 1 for solving the above-mentioned problem is as follows.
An apparatus for performing a radiation transmission test on a circumferential welded portion of a cylindrical member in a plant facility,
A support means for detachably mounting the inside of the cylindrical member, supporting a radiation source for testing at the center of the cylindrical member;
A guide pipe extending from the outside of the cylindrical member to the support means through the cylindrical member, to which the radiation source is movable.

The means described in claim 10 for solving the above problem is as follows.
A method for performing a radiation transmission test on a circumferential welded portion of the tubular member using the radiation transmission test apparatus according to any one of claims 1 to 9,
Mounting the support means and the guide pipe inside the cylindrical member,
The cylindrical member is moved to a predetermined position, and circumferential welding is performed on its end,
Insert a test radiation source into the guide pipe from the outside of the cylindrical member,
Moving the radiation source to a position facing the circumferential welded portion of the guide pipe in a radial direction;
The soundness of the circumferential welded portion is tested by observing radiation from the outside of the cylindrical member.

That is, in the radiation transmission test apparatus and the test method using the same of the present invention, the support means and the guide pipe are mounted in advance inside the cylindrical member, and after the new circumferential welding of the cylindrical member is completed, the guide pipe A test radiation source is inserted inside, and a radiation transmission test of a new circumferential weld is performed.
This eliminates the need for workers performing the radiation transmission test to remain inside the cylindrical member for a long time, which not only reduces the exposure dose of the worker but also greatly improves the workability of the radiation transmission test. Can be made.

  In addition, the radiation transmission test apparatus according to claim 1 may further include a pulling means for pulling the support means and collecting the support means outside the cylindrical member.

Further, the support means may be provided with a plurality of support legs that can swing between a mounted state in contact with the inner wall surface of the cylindrical member and a detached state spaced from the inner wall surface.
At this time, a part of the plurality of support legs can be configured to be extendable and a biasing unit that presses the distal ends of the extendable support legs against the inner wall surface of the cylindrical member can be further provided.
The support leg may be provided with a rolling member that rolls on the inner wall surface of the cylindrical member at the tip thereof.
In addition, the support leg can be provided with a sliding member that can slide smoothly on the inner wall surface of the cylindrical member at the tip thereof.
Further, the support leg can be configured to swing in a detached state when the support means is pulled by the pulling means.

  Further, in the radiation transmission test apparatus according to claim 1, the support means expands and contracts between a mounted state that extends toward the inner wall surface of the cylindrical member and a detached state that contracts and separates from the inner wall surface. It can have a plurality of flexible support legs.

  Further, the radiation transmission test apparatus according to claim 1 may further include a camera for monitoring a back wave of the circumferential weld.

In the radiation transmission test method described in claim 10, the cylindrical member can be a nozzle of a steam generator, an elbow connected to the nozzle, or a cooling pipe.
And the said support means can be mounted | worn inside the said nozzle, the said elbow, or the said cooling piping.
At this time, a worker who has entered the water chamber of the steam generator can wear the support means.
Furthermore, the support means can be attached to a plurality of locations of the cylindrical member, respectively.
In addition, the radiation transmission test apparatus can be recovered outside the tubular member by pulling a rope connected to the support means.

  According to the present invention, for example, when performing a radiation transmission test in a plant such as a pressurized water reactor that has undergone repair work, a radiation transmission test apparatus that can improve workability while reducing the exposure dose of the worker. And a test method can be provided.

  Hereinafter, an embodiment of a radiation transmission test apparatus and a test method according to the present invention will be described in detail with reference to FIGS.

  The radiation transmission test apparatus 100 according to the first embodiment shown in FIG. 1 includes an RT cradle 30, a guide pipe, a connection fitting, and the like. FIG. 1 is a front view of the RT cradle 30, FIGS. 2 and 3 are partial perspective views thereof, and FIG. 4 shows a state in which the legs are folded.

  The RT cradle 30 shown in FIG. 1 has an inner cylinder 31, an outer cylinder 32, a pair of fixed legs 33, and a pair of telescopic legs 34. A groove 31a is recessed in the outer peripheral surface of the inner cylinder 31, and the inner cylinder 31 and the outer cylinder 32 can be smoothly slid relative to each other by inserting a convex portion of a guide 35 attached to the outer cylinder 32. It has become. A handle 36 is attached to the inner cylinder 31.

  Each of the pair of fixed legs 33 and the pair of extendable legs 34 has a base portion, a leg portion, and a head portion. The length of the fixed leg 33 is fixed, but the length of the extendable leg 34 has a length. It can be expanded and contracted.

  As shown in FIG. 4, the fixed base 33 has a first base portion 38 attached to the inner cylinder 31 and a second base portion 39 attached to the outer cylinder 32.

  As shown in FIG. 4, the telescopic legs 34 have a first base portion 38 attached to the inner cylinder 31 and a second base portion 39 attached to the outer cylinder 32. Further, as shown in FIG. 3, a cylinder or a spring is used for the head portion 37, and the new elbow 14 to which the RT cradle 30 is attached and the inner wall of the new nozzle 15 are pressed, thereby the RT cradle 30. Can be fixed. At this time, the inner diameter of the portion to which the RT cradle 30 is attached is measured in advance, and the lengths of the pair of fixed legs 33 are adjusted in advance so that the center of the RT cradle 30 coincides with the center of the mounting portion. The radiation source can be arranged in the center of the mounting part.

Accordingly, when the handle 36 attached to the inner cylinder 31 is pulled, the inner cylinder 31 slides in the axial direction relative to the outer cylinder 32 together with the handle 36, and the fixed leg 33 and the extendable leg 34 can be folded. Therefore, the RT cradle 30 can be removed from the pipe 15, the nozzle 16, and the elbow 17 and taken out from the water chamber 8.
By attaching a roller or a wheel to the tip of the head portion 37 of the fixed leg 33 and the telescopic leg 34, the inner surface of the pipe 15, the nozzle 16, and the elbow 17 is damaged when the fixed leg 33 is folded and removed. Can be prevented.

  The inner cylinder 31 has a structure that can be assembled with a guide pipe by incorporating a collet chuck, for example. By attaching a welding back wave monitoring camera to the outer peripheral portion of the outer cylinder 32 or the front surface of the inner cylinder 31, the back wave can be confirmed after the first layer welding of the new peripheral welding.

  The above-described RT cradle 30 shows an example thereof, and does not limit the present invention. For example, even if there are three or five legs, the same effect can be obtained.

  In addition, as shown in FIG. 5, a similar effect can be obtained by combining a single-stage or multi-stage extendable / contractible leg 41 with the central portion of the RT cradle 40.

  Next, with reference to FIGS. 6-9, the case where the inlet nozzle 7 and the elbow 13 of the steam generator 3 are cut | disconnected and the new elbow 14 and the new nozzle 15 are attached is demonstrated.

  As shown in FIG. 6, when the new elbow 14 and the new nozzle 15 are attached to the inlet nozzle 7 of the steam generator 3, first, a pair of RT cradles 30 </ b> A are placed inside the new elbow 14 and the new nozzle 15 in advance. , 30B is installed. Then, the radiation source is moved to the positions of the new circumferential weld lines 16, 17 and 18 through the guide pipes 51 and 52 supported by these RT cradles 30A and 30B.

  Specifically, before attaching the new elbow 14 and the new nozzle 15, the pair of RT cradles 30 </ b> A and 30 </ b> B and the guide pipe 51 are assembled in advance and installed inside both ends of the new elbow 14. And the new elbow 14 is moved to the extent which overlaps with the primary coolant piping 19 half. Next, the guide pipe 52 is inserted through the opening of the water chamber 8 and sent to the inlet nozzle 7, and is connected to the end of the guide pipe 51 supported by the RT cradle 30 </ b> B via the joint 53. Thereafter, the new elbow 14 is further moved, and circumferential weldings 16 and 18 between the inlet nozzle 7 and the primary coolant pipe 19 are performed.

  After carrying out the circumferential welding 16, 18, a radiation source is inserted and transferred from the end of the guide pipe 52, and a radiation transmission test is performed. At this time, the position where the pair of RT cradle 30A, 30B is installed is a dimension position determined from the groove surface of the new elbow 14, and the length of the guide pipes 51, 52 and the dimension of the new elbow 14 are measured in advance. Keep it. Thereby, since the position of the new circumference welding lines 16, 17, and 18 can be calculated, the transfer distance of a radiation source can be determined.

  After completing the radiation transmission test, the handle 36 of the RT cradle 30A, 30B is pulled, the fixed leg 33 and the extendable leg 34 are folded, and then carried out of the steam generator 3.

  The RT cradle 30A, 30B can be removed by an operator entering the water chamber 8 of the steam generator 3 and hooking the hook 61 or the like on the handle 36 as shown in FIG. Further, when the RT cradle 30A, 30B is installed in the new elbow 14, one end of a rope or the like is attached to the handle 36 in advance, and the other end is pulled out from the opening of the steam generator 3 to generate steam. It is also possible to pull this rope from the outside of the vessel 3 to remove and carry it out.

  That is, by using the radiation transmission test apparatus 100 of the present embodiment, it is possible to reduce the exposure dose of the worker and shorten the work time.

Next, with reference to FIG. 8, different installation states of the radiation transmission test apparatus will be described.
The difference from the installed state shown in FIG. 6 is that only a part of the inlet nozzle 7 of the steam generator 3 is cut and a new nozzle 15 is welded.

  As shown in FIG. 8, the RT cradle 30 is installed inside the inlet nozzle 7 of the steam generator 3, and the guide pipe 54 is inserted from the opening of the water chamber 8 and assembled to the RT cradle 30. Thereafter, a new nozzle 15 is installed, and new circumferential welds 16 and 17 are performed to perform a radiation transmission test. The transfer of the radiation source is the same as in FIG. In this case, the same effect as that shown in FIG. 6 can be obtained.

  Next, the different installation states of the radiation transmission test apparatus will be described with reference to FIG. The difference from the installation state shown in FIG. 6 is that the RT cradle 30 is installed inside the primary coolant pipe 19 and the inlet nozzle 7 of the steam generator 3.

As shown in FIG. 9, a pair of RT cradles 30 </ b> A and 30 </ b> B are installed inside the primary coolant pipe 19 and the inlet nozzle 7 of the steam generator 3. The guide pipe 51 is previously disposed inside the water chamber 8 or the inlet nozzle 7, and the new elbow 14 is moved to the extent that it overlaps with the primary coolant pipe 19.
Next, the guide pipe 51 is assembled into the pair of RT cradles 30A and 30B, and the new elbow 14 is further moved.
Then, the new elbow 14 is circumferentially welded to the inlet nozzle 7 and the primary coolant pipe 19, respectively, and a radiation transmission test is performed. The transfer of the radiation source is the same as that shown in FIG. Even in this case, the same effect can be obtained.

  In the case shown in FIGS. 6 to 9, a part of the radiation transmission test apparatus 100 such as the RT cradle 30B and the guide pipe 52 on the steam generator 3 side is placed inside the water chamber 8 by the operator. Can be installed. Although the exposure dose received by the worker at this time increases, the radiation exposure test apparatus 100 is partially installed and the radiation source is transferred from the outside of the steam generator 3 to reduce the exposure dose of the worker and work. Time can be shortened.

The front view which shows RT cradle. The disassembled perspective view which shows the center part of RT cradle. The disassembled perspective view which shows the leg part of RT cradle. The side view which shows the state which folded the leg part of RT cradle. The front view which shows other embodiment of RT cradle. The figure which shows the use condition of a radiation transmission test apparatus. The figure explaining removal of RT cradle. The figure which shows the use condition of a radiation transmission test apparatus. The figure which shows the use condition of a radiation transmission test apparatus. Schematic which shows the primary cooling equipment system | strain of a pressurized water reactor. Schematic which shows the lower structure of a steam generator. Schematic which shows the structure of a reactor vessel. The figure explaining replacement repair work of a steam generator nozzle. The figure explaining replacement repair work of a steam generator nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor containment vessel 2 Reactor vessel 3 Steam generator 4 Primary coolant pump 5 Pressurizer 6 Outlet nozzle 7 Inlet nozzle 8 Water chamber 10 Heat transfer tube 11 Outlet nozzle 12 Inlet nozzle 13 Elbow 14 New elbow 15 New nozzle 16, 17 , 18 New circumferential weld line 19 Primary cooling pipe 30 RT cradle 31 Inner tube 32 Outer tube 33 Fixed leg 34 Telescopic leg 35 Guide 36 Handle 37 Head part 38 First base part 39 Second base part 40 RT cradle 41 Telescopic legs 51, 52 Guide pipe 53 Joint 54 Guide pipe 61 Hook 100 Radiation transmission test apparatus 110 of one embodiment Radiation transmission test apparatus of a modification

Claims (12)

An apparatus for performing a radiation transmission test on a circumferential welded portion of a cylindrical member in a plant facility,
A plurality of support legs for supporting a test radiation source at the center of the cylindrical member , including a plurality of fixed legs and a biasing means for pressing a tip against an inner wall surface of the cylindrical member. A plurality of support legs, an inner cylinder to which the plurality of support legs are swingably attached, an outer cylinder that is slidable relative to the inner cylinder in the axial direction, and the outer cylinder And a support unit that is detachably mounted inside the cylindrical member , and a link that connects each of the support legs and a handle attached to the inner cylinder ,
A guide pipe that extends from the outside of the cylindrical member to the support means through the cylindrical member, in which the radiation source is movable,
Traction means for pulling the support means and collecting it outside the tubular member,
A mounting state in which the support leg of the support means is pressed against the inner wall surface of the cylindrical member by being pressed by the urging means, and a detachment separated from the inner wall surface by the handle being pulled by the pulling means. radiographic examination apparatus according to claim swing to Rukoto between the states.   The radiation transmission test apparatus according to claim 1, wherein the support leg has a rolling member that rolls on an inner wall surface of the cylindrical member at a tip thereof.   2. The radiation transmission test apparatus according to claim 1, wherein the support leg has a sliding member that can slide smoothly on an inner wall surface of the cylindrical member at a tip thereof. Radiographic examination apparatus as claimed in any one of claims 1 to 3, further comprising a camera for monitoring the penetration bead of the peripheral weld. A method for performing a radiation transmission test on a circumferential welded portion of the cylindrical member using the radiation transmission test apparatus according to any one of claims 1 to 4 ,
Pressing the urging means of the telescopic leg and installing the support means in an installed state inside the cylindrical member and attaching the guide pipe to the support means,
The cylindrical member is moved to a predetermined position, and circumferential welding is performed on its end,
Insert a test radiation source into the guide pipe from the outside of the cylindrical member,
Moving the radiation source to a position facing the circumferential welded portion of the guide pipe in a radial direction;
Test the soundness of the circumferential weld by observing radiation from the outside of the tubular member,
A radiation transmission test method, wherein the support means is removed from the tubular member by pulling the handle by the pulling means after the test. 6. The radiation transmission test method according to claim 5 , wherein the cylindrical member is a nozzle of a steam generator, an elbow connected to the nozzle, or a cooling pipe. The radiation transmission test method according to claim 6 , wherein the support means is mounted inside the nozzle. The radiation transmission test method according to claim 6 , wherein the support means is mounted inside the elbow. The radiation transmission test method according to claim 6 , wherein the support means is mounted inside the cooling pipe. Radiographic examination method described in any one of claims 7 to 9 workers entering the interior of the water chamber of the steam generator is characterized in that mounting the support means. The radiation transmission test method according to claim 5 , wherein the support means is attached to each of a plurality of locations of the cylindrical member. 6. The radiation transmission test method according to claim 5 , wherein the radiation transmission test device is recovered outside the cylindrical member by pulling a rope connected to the support means.

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